Pulse generator



July 27, 1948. J. A. RADO PULSE GENERATOR Filed March 14, 1945 ll A H A14 A H A o xmosfiz Edema;

m Y m g R m IN T H A O J Patented July 27, 1948 PULSE GENERATOR John A.Rado, Little Neck, N. Y., assignor, by

mesne assignments, to

Hazeltine Research,

Inc., Chicago, 111., a corporation of Illinois Application March 14,1945, Serial No. 582,662

14 Claims. 1

This invention relates, in general, to pulse generators and isparticularly directed to high-frequency pulse generators for developinga plurality of time-spaced pulses bythe periodic charging anddischarging of energy-storage devices. The term high-frequency pulsegenerator is here used to designate an arrangement for producing pulseswhich have a high repetition frequency, or a short time separation.

For some purposes it is desirable to develop large amounts of power forshort time intervals and at relatively high repetition rates fromlowvoltage, low-power sources. Heretofore, there have been employedgenerators which utilize energy storage devices that are periodicallycharged in a suitable manner from sources of the foregoing type, and arethen discharged through gas-filled electron-discharge means to producelarge values of power in an output circuit. Pulse-forming networks, orartificial transmission-line sections have been proposed for use as theenergy-storage devices, since they are capable of delivering pulses ofenergy having substantially rectangular wave form and controllabledurations which may be exceedingly short, for example, of the order of amicrosecond. Hence, such high-power generators are suited to thedevelopment of periodic pulses having relatively high repetitionfrequencies.

Gas-filled electron-discharge means or tubes are particularly useful inarrangements of the foregoing character for discharging transmissionlinesections, since these tubes, when conductive, have low anode-cathodeimpedances and low internal losses, and are able to conduct much largercurrents than vacuum tubes of corresponding physical dimensions becauseof electron augmentation due to impact with gas molecules. Consequently,to develop a given amount of power, the operating potentials requiredfor gas-filled tubes may be of considerably lower values, thuseliminating the need for high-voltage equipment, rigorousinsulation-breakdown precautions, and shock safeguards.

However, in a pulse generator of the type in which output pulses areproduced by periodically discharging an energy-storage device through agas tube, the recharging of the energy-storage device, following eachdischarge thereof, must be carefully controlled. Specifically, storagedevice must be recharged by a suitable means which is effective to limitthe current flow through the discharge tube during the deionizationinterval thereof to a value less than that required to sustainionization. Various charging the energycircuits have been employed tocontrol the recharging process. For example, linear-chargingarrangements have been used. Such arrangements include a resistor ofrelatively high value for providing a charging interval that is longwith respect to the deionization interval of the discharge tube, butthis characteristic is objectionable when high-frequency operation isdesired.

In other prior arrangements, faster charging is accomplished byreplacing the resistor in the charging circuits with a series inductancewhich resonates with the capacitance of the energystorage device. Theseother prior arrangements produce output pulses with a minimum timeseparation which approaches the deionization interval of the dischargetube. This limitation becomes significant Where even a shorter timeseparation of the generated pulses is required.

It is an object of the present invention, therefore, to provide ahigh-frequency pulse generator which substantially avoids theaforementioned limitations of prior art arrangements.

It is another object of the invention to provide an improvedhigh-frequency pulse generator including a plurality of energy-storagedevices to be discharged through a common gas-filled device to generatea plurality of time-spaced pulses having a maximum separation which isless than the deionization interval of the gas-filled device.

It is a specific object of the invention to provide an improvedhigh-frequency pulse generator including a plurality of energy-storagedevices arranged consecutively to be discharged through a commongas-filled device to produce a plurality of output pulses havingsubstantially equal amplitudes and pulse durations.

A high-frequency pulse generator for generating a plurality oftime-spaced pulses in accordance with the present invention comprises aplurality of energy-storage devices and means for charging theenergy-storage devices. The generator includes gas filled electrondischarge means having a predetermined deionization characteristic andadapted to provide a single discharge path common to each of theplurality of energy-storage devices. The generator further includesmeans for successively completing discharge circuits through the singledischarge path provided by the gas-filled means from each of theenergy-storage devices in a predetermined sequence with a timeseparation between succeeding steps of the sequence which is less thanthe deionization interval of the gas-filled means, consecutively todischarge the plurality of energystorage devices and produce acorresponding plu- 3 rality of output pulses having a. predeterminedtime separation.

For a better understanding of the present invention, together with otherand further objects thereof, reference is had to the followingdescription taken in connection with the accompanying drawing, and itsscope will be pointed out in the appended claims.

In the drawing, Fig. l is a schematic representation of a high-frequencypulse generator in accordance with the invention; and Fig. 2 includes ta series of graphs utilized in explaining the operation of the Fig. 1arrangement.

Referring now more particularly to Fig. 1, there is represented ahigh-frequency pulse generator for generating a plurality'of'time-spaced pulses. The illustrated arrangement, when keyed intooperation by an applied control signal, produces a pair of time-spacedpulses having. a de-.

sired duration and time separation. The generator includes a plurality,more specifically a pair, of energy-storage devices individuallyhavingthe form of an artificial'or simulated transmission-line section.One such line section It has high-potential terminals H, H and alowpotential terminal Hi. The line is formed of lumped circuit elements,including series-connected inductors t2, [2, i2 and intermediate shuntcondensers l3, i3, is arranged to simulate a transmission line. Asufficient number of series and shunt elements is provided so that linesection iii, in discharging, may deliver energy to a load circuitsubstantially continuously during a desired pulse interval. The pulseinterval is determined by the product of the total inductance and totalcapacitance of the line section, which is'selected in accordance withthe desired pulse duration. A damping resistor i5 is bridged acrossinductor elements l2, it.

The other line section it, which is also utilized as an energy-storagedevice in the generator, has a similar construction and includes ahigh-potential terminal 2t: and a low-potential terminal 25. It isformed of lumped circuit elements shown as series-connected inductorsll, ii and shunt-connected condensers it, l8, IS. A damping resistor isis bridged across inductors ll, ll.

Where, as in the embodiment under consideration, it is desiredtogenerate paired pulses having equal pulse durations, line sections Hiand it are so constructed that theproduct of the total inductance andtotal capacitance of each section is equal to a preselected constantvalue. While this product is the same for both sections, the condensersof line section iii are selectedso that the total capacitance of thissection exceeds that of section it. The purpose of this selectionwill bemade clear hereinafter. In view of the described relationship of theinductance and capacitance of the line sections, the lines, if made ofuniformly distributedparameters, have different characteristicimpedances. However, in the pre ferred generator construction, the linesections are connected in cascade during a portion of thepulse-generating process and, therefore, it is preferable that each takethe form of a tapered transmission line in order that this connectionmay be effected with substantial impedance matching to avoid reflectionphenomena. To this end, the series-inductance and shunt-capacitanceelements are selected so that each line section has the aforementionedinductance-capacitanceproduct and an impedance characteristic whichvaries from a maximum at one end to a minimum at theopposite end.. Asillustrated, terminal of line section it is coupled to terminal 28 ofline section it, and the construction is such that the impedances at theadjacent ends of the sections are substantially matched.

A unidirectional conductive device, provided by a diode 25, connectsterminal 2| of line section it with terminal M of line section Hi,completing a arallel circuit arrangement. Means are coupled to thiparallel arrangement for simultaneously charging each of the linesections to a particular level. This means consists of a source ofunidirectional potential, indicated +13, coupled to the junction ofterminals H and 25 by way of a duo-diode 2t and a saturable charginginductor 2?. The charging circuit is completed by a ground connection28. Inductor 27 represents the major inductive reactance of thedescribed charging circuit and is selected of such value as to form,with the total capacitance of the two line sections it and it, aseries-resonant charging circuit. The circuit is resonant at a frequencyapproximately equal'to one-half the maximumrepetition frequency of thepaired pulses.

The generator also includes a gas-filled: tetrode Stl, constitutinggas-filled electron-discharge means having a predetermined deionizationcharacteristic, for discharging each of line sections is and it. Thecathode of tube 30 is maintained at ground potential, and abias-potential source ill and grid resistor 32 apply an operating biasto the control electrode thereof for normally maintaining the tube in anonconductive condition. A similar potential source 33 applies anegative potential to the shield electrode of the tube.

The primary winding of a pulse transformer 35 power transfer isobtainable from the generator to a load, represented by resistor 36coupled to the secondary winding of pulse transformer 35.

There are also provided in the generator, selectively operable switchinmeans for coupling the other line section M5 to tube 36. This means-isa'unidirectionally conductive device comprising a second gas-filled tube58 of the tetrode type. The cathode of tube 4E3 is coupled tolow-potential terminal 2! of line section it, while its anodeisconductively coupled to the cathode of the first gas tube 38, providinga loop circuit from linesection It through line section Ill andtubes-wand Ml; Tube 50 is normally maintained in a nonconductivecondition by means of a bias-potential source ll coupled between itscathode and control electrode through the secondary Winding of apulse'transformer 42 and a resistor-4 3; The shield electrode is biasedto a suitable operating potential through a second source 44.ode-cathode circuits of tubes 25- and 40', which couple the1ow-potentia1 terminal 2! ofline section it to ground, are conductive inopposite senses, one being utilized in the line-charging process and theother in the line-discharging process, as will be made clearhereinafter.

Finally, the generator has means for successively completing dischargepaths through; gasfilled tube 33 from each of. the plurality ofenergy-storage devices Of the generator in a predetermined time sequencewith a time separation between succeeding steps of the sequence whichPreferably, the

St is rendered conductive, a matching The an-' 5. is less than thedeionization interval of tube 30, consecutively to discharge each of theenergystorage devices to produce a corresponding plurality of outputpulses having a predetermined time separation. This means includes apair of terminals 50, o coupled to the input circuit of tube through acondenser 5| for applying a control signal to initiate an electrondischarge within this tube. The means under consideration forsuccessively completing discharge paths for the energy-storage devicesalso includes a timedelay network 52 having input terminals 54, 54coupled across terminals 50, 5B. Delay network '52 is short-circuited atits remote terminals, as indicated at 53. The network may have anyconventional construction and is selected to effect a predeterminedtotal delay of an applied pulse, the delay being less than thedeionization interval of tube 36, for any operating condition to beencountered. The primary winding of transformer 42 is coupled to inputterminals 54, 54 of the delay network to apply a delayed control signalderived therefrom to the control electrode of the second gas-filled tube40. A resistor 55 is coupled across this winding of transformer 42 toterminate network 52 in its characteristic impedance. The windings oftransformer 42 are poled to obtain a polarity reversal of signalsapplied to its primary winding.

In considering the operation of the described generator, it will beassumed that both gas tubes 30 and 4B are in their normal nonconductivecondition and that line sections I5 and It are acquiring a charge fromsource +B. The charging circuit for line section :6 is completed throughdiode 25 and the line sections are charged in parallel. When thecharging process has been completed, the voltage established across thehighand lowpotential terminals of each line section approaches twice +B.The magnitude of the line potential results from the fact that in aseries-resonant charging circuit, the potential developed across itsinductive or capacitive reactance may readily approach twice the valueof the charging source. This potential at the line terminals raises thepotential level of the cathode elements of charging tube 26 acorresponding amount, biasing this tube to anode-current cutofi andinterrupting the charging circuit. The generator is now in condition torespond to an applied keying or control signal applied to inputterminals 50, 50 to supply to load impedance a pair of time-spacedpulses.

The curves of Fig. 2 represent the response of the generator to such akeying signal. In this figure, curve A represents the keying signal, andcurves B and C indicate the resulting control pulses applied to thecontrol electrodes of tubes 30 and 49, respectively. Curves D and Edesignate, respectively, the potential relative to ground of the anodeof tube 39 and the cathode of tube 4% Curve F represents the pulsesgenerated in response to the discharging of line sections In and I6, andcurve G shows these pulses as applied to load impedance 36.

At a time to immediately precedin the application of the control orkeying signal, both line sections are fully charged as stated above. Theanode and cathode of tube 30 are directly coupled between high-potentialterminal I l and lowpotential terminal I4 of line section 10, causingthe anode potential to be at approximately twice the value of source +B.However, the anode and cathode electrodes of tube 40 are coupled acrossthe high-potential terminal 20 and low-potential the value of thecharging source terminal 2| of line section [6 through a seriescircuitarrangement in which the line sections it) and I6 are connected in phaseopposition. Since the lines have identical charge conditions, thecathode of tube 40 is at Zero potential with reference to ground. Thedescribed potential conditions are represented in curves D and E of Fig.2.

At the time t1 the keying signal of curve A, a pulse of positivepolarity, is applied to terminals 50, 50. It is directly applied withthe same polarity to the control electrode of tube 30 and to the inputterminals of delay network 52, and is applied with reversed polaritythrough transformer 42 to the control electrode of tube 40, as shown bycurves B and C. The control signal initiates an electron discharge intube 30 but has no effect on tube 40 which remains in its nonccnductivecondition.

With tube 30 rendered conductive, a discharge path is completed for linesection I0, extending from terminal Il' through the primary winding oftransformer 35 and tube 30 to terminal l4. Transformer 35 terminates oneend of line section H3 in a matching impedance, while the opposite endthereof is open-circuited since each of tubes 25, 2B, and 40 isnonconductive. Thereupon, line section I0 completely discharges,generating a pulse Pi which is applied directly to the load impedance36. The duration Ta of pulse P1 corresponds to the time interval t1-t2required completely to discharge line section l6. It is determined bythe parameters of the line section, being approximately equal to twicethe geometric mean of its total inductance and total capacitance.

The discharge of line section l0 effectively grounds terminals H, l I ofline section It) as well as the adjacent terminal 20 of line section I6.This removes the holding voltage established on the cathode elements ofdiode 26 when both line sections are fully charged, and causes thecathode potential of tube 48 to shift, becoming negative with respect toground by approximately 2B or the potential of line section I6. With theholding voltage removed from diode 26, the charging circuit is completedand recharging of line section It! is started. However, the saturablereactor 21 has a high initial inductance and so limits the current flowin the charging circuit that no appreciable charge is established online section 10 during the deionization interval of tube 30. Thedeionization interval of tube 30 is the time required for the gasincluded therein to deionize following the occurrence of an electrondischarge and the ionization of the gas incident thereto.

The deionization interval is determined by the characteristics of thetube and the operating conditions of the generator. For the case underconsideration, it is indicated tz-ts. Consequently, at the time is, thefollowing conditions exist in the generator: the first pulse P1 has beenproduced; the anode of tube 30 is at substantially ground potential;tube 40 is in its normal nonconductive state but its cathode has anegative potential relative to ground approximately equal to twice thevalue of source +13; and the deionization process of tube 3D hasstarted.

After a preselected time interval represented tz-ts, corresponding tothe total time delay of network 52, a reflection of the keying signal ofcurve A appears at the network terminals 54, 54. The reflected signalresults from the short-circuited termination 53 and is of negativepolarity. It is applied directly to the control electrode of tube 30,but has no effect on this tube which continuesto deionize. The reflectedor delayed control signal is also applied to the control electrode oftube 40, but with positive polarity, receiving a polarity reversal intranslation through transformer 42. The delayed control signal renderstube 40 conductive at time ts, which is delayed with reference to timeis such that the interval tz-ts is less than the deionization intervalof tube 30.

At time ts, line section Iii-remains terminated in a matching impedanceat terminal M since tube 30 is still ionized. The connection betweenterminals I I and of line sections it and Iii, respectively, couples theadjacent ends of these sections with substantially matched impedances.Terminal '2I, at the opposite end of line section it, is effectivelygrounded through conductive tube 40, completing a discharge path forline section it. This path extends from terminal 20 through line sectionI 0, pulse transformer 35, tubes 3t and 3B in series, to terminal 2 I.The described discharge circuit establishes thesame terminal conditionsfor line section I6 as those of line section M when tube is. initiallyrendered conductive to generate thefirstpulse P1. Namely, one end ofline section I6 is terminated in a matched impedance by line section I0,while the opposite end thereof, including terminal 2i, isopen-circuited. Conse quently, line section 16 discharges in a mannersimilar to the discharge of line section ducin at terminal 20 a secondpulse P2 of curve F. The duration of this pulse corresponds to the timeinterval ifs-t4 required completely to discharge line section I0. PulseP2 is directly applied to terminal I I of line section Hi and istranslated th'erethrough, in conventional manner, to load impedance 36by Way of pulse transformer 35. Since the second pulse P2 is generatedin one line section and traverses the other in reaching the load36,it'is first pulse P1 by a total time delay indicated Ts in curve G. Theinterval TS includes the total time delay t1t3 of delay network 52, plusthe one-way delay of line section I 0.

Shortly after time is, when deionization has been completed in tube to,charging reactor 2? becomes saturated and line sections iii and it arerapidly recharged to approximately twice the value of source +13. Sincethe anode potential of tube 3i] is determined by the charge condition ofline section iii, the wave form of curve D, during theintervalifollowing the deionization period of tube 30, may represent therecharging process. At the end ofthis process, the potential conditiondescribed in connection with the time to are reestablished and thegenerator is conditioned to respond to the next succeeding controlsignal to generate a further pair of time-spaced pulses P1 and P2 havinga desired duration and time separation.

The generated pulses P1 and P2 have equal pulse. durations Ta since eachof line sections it and I6 has the same inductanc -capaci'tance product.However, condensers i3, l8, it of line section I6 have a greater totalcapacitance than condensers I2, I2, I2 of line section Iii, in orderthat the paired pulses P1 and P2 may also have substantially the sameamplitudes. In this connection, it will be noted that the onlyimpedances in the discharge path of line section l0 correspond to thoseof transformer anddischarge tubeti On the other hand, the discharge pathof line section I6 includes additional impedance elements, such. as :thesecond gas tube 50. By proporti-oning thecapacitances ofrlines Iflandlfiwith reference 50, pro- 1 5 delayed with reference to the to theimpedances of their respective discharge paths, the output pulses P1 andPzmay have equal amplitudes.

Although the invention has been described in connection with anarrangement including but a pair of energy-storage devices individuallyto be discharged .to generate a pair of time-spaced pulses, it will beunderstood that more energystorage devices may be provided if desired.Each of the energy-storage devices is to be discharged through thecommon discharge tube 30. This may be efiected by any suitable meanswhich consecutively couples the energy-storage devices to the commondischarge tube in a time sequence such that the succeeding steps of thesequence have a time separation which is less than the deionizationinterval of the discharge tube. Where this procedure is followed,discharge paths are consecutively completed through the common dischargedevice in a desired succession to discharge each of the devices andgenerate a corresponding plurality of time-spaced pulses having apreselected time separation. The time separation of the resulting pulsesis determined largely by the preselected time sequence in accordancewith wiich discharge circuits for the individual stordevices arecompleted through the common discharge tube.

It will be apparent that the line sections it and it need not beartificial lines constructed of lumped circuit parameters as described.Conventional distributed-constant line sections maybe employed, ifdesired.

Pulse generators of the type described above may be utilized incommunication systems for applying potential pulses to the anode of oneor more tubes in the power oscillator circuit of a transmitter.

While applicant does not wish the invention to be limited to anyspecific circuit constants, the following circuit constants are given asillustrative of values of circuit elements which may be utilized in thecircuit of Fig. 1.

3.0 microhenries 2.0 m-icrohenries 0.1 henry 0.02 microfarad 0.05microfarad 0.025 microfarad Inductors 12 and 17 Inductor l2 Inductor 2'7Condensers -13 Condensers 18 Condenser 18 Resistors 15and 19 ohmsResistor 38 1.1 kilohms Resistor 3-2 4'7 kilohms Resistor 55 680 ohmsResistor 43 10 kilohms 5 to 1 turns ratio 1 to 1 turns ratio Transformer35 Transformer 42 Tube 26 Type 6X5GT/G- Tubes 30 and 40 Type 2D21 Tube25 Type 6H6 Grid bias of tube 30 12.0 volts Grid bias of tube 40 9.0volts Shield grid bias of tubes 30 and 40 -1.5 volts +3 potential 300volts What is claimed is:

1. A high-frequency pulse generator for generating a plurality oftime-spaced pulses comprising, a plurality of energy-storage devices,means for charging said energy-storage devices, gas-filledelectron-discharge means having a predetermined deionizationcharacteristic and adapted to provide a single discharge path common toeach of said plurality of energy-storage devices, and means forsuccessively completing discharge circuits through said single dischargepath provided by said gas-filled means from each of said energy-storagedevices in a predetermined sequence with a time separation betweensucceeding steps of said sequence less than the deionization interval ofsaid gas-filled means consecutively to discharge said plurality ofenergy-storage devices to produce a corresponding plurality of outputpulses having a predetermined time separation.

2. A high-frequency pulse generator for generating a plurality oftime-spaced pulses comprising, a plurality of energy-storage devices,means for charging said energy-storage devices, gas-filledelectron-discharge means having a predetermined deionizationcharacteristic and adapted to provide a single discharge path common toeach of said plurality of energy-storage devices, and means forsuccessively completing discharge circuits through said single dischargepath provided by said gas-filled means from each of said energy-storagedevices in a predetermined sequence with a time separation betweensucceeding steps of said sequence less than the deionization interval ofsaid gas-filled means consecutively to discharge said plurality ofenergystorage devices to produce a corresponding p1urality oftime-spaced pulses having a predetermined polarity and occurring in apredetermined time sequence.

3. A high-frequency pulse generator for generating a plurality oftime-spaced pulses comprising, a plurality of energy-storage devices,means for simultaneously charging said energystorage devices, gas-filledelectron-discharge means having a predetermined deionizationcharacteristic and adapted to provide a single discharge path common toeach of said plurality of energy-storage devices, and means forsuccessively completing discharge circuits through said single dischargepath provided by said gas-filled means from each of said energy-storagedevices in a predetermined sequence with a time separation betweensucceeding steps of said sequence less than the deionization interval ofsaid gasfilled means consecutively to discharge said plurality ofenergy-storage devices to produce a corresponding plurality of outputpulses having a predetermined time separation.

4. A high-frequency pulse generator for generating a plurality oftime-spaced pulses comprising, a plurality of energy-storage devices,means for simultaneously charging said energystorage devices inparallel, gas-filled electrondischarge means having a predetermineddeionization characteristic and adapted to provide a single dischargepath common to each of said plurality of energy-storage devices, andmeans for successively completing discharge circuits through said singledischarge path provided by said gasfilled means from each of saidenergy-storage devices in a predetermined sequence with a timeseparation between succeeding steps of said sequence less than thedeionization interval of said gas-filled means consecutively todischarge said plurality of energy-storage devices to produce acorresponding plurality of output pulses having a predetermined timeseparation.

5. A high-frequency pulse generator for generating a plurality oftime-spaced pulses comprising, a plurality of energy-storage devices,means for chargin said energy-storage devices, gas-filled electrondischarge means having a predetermined deionization characteristic andadapted to provide a single discharge path common to each of saidplurality of energy-storage devices but normally maintained in anonconductive condition, and means for initiating an.

electron discharge in said gas-filled means and for successivelycompleting discharge circuits through said single discharge pathprovided by said gas-filled means from each of said energystoragedevices in a predetermined sequence with a time separation betweensucceeding steps of said sequence less than the deionization interval ofsaid gas-filled means consecutively to discharge said plurality ofenergy-storage devices to produce a corresponding plurality of outputpulses having a predetermined time separation.

6. A high-frequency pulse generator for generating a plurality oftime-spaced pulses comprising, a plurality of energy-storage devices,means for charging said energy-storage devices, gas-filledelectron-discharge means having a predetermined deionizationcharacteristic for discharging each of said plurality of energy-storagedevices, and means including a time-delay network for successivelycompleting discharge paths through said gas-filled means from eachofsaid energy-storage devices in a predetermined sequence with a timeseparation between succeeding steps of said sequence less than thedeionization interval of said gas-filled means consecutively todischarge said plurality of energy-storage devices to produce acorresponding plurality of output pulses having a predetermined timeseparation.

7. A high-frequency pulse generator for generating a pair of time-spacedpulses comprising, a pair of energy-storage devices, means for chargingsaid energy-storage devices, gas-filled electron-discharge means havinga predetermined deionization characteristic and adapted to provide asingle discharge path common to each of said energy-storage devices, andmeans for successively completing discharge circuits through said singledischarge path provided by said gasfilled means from each of saidenergy-storage devices with a time separation therebetween less than thedeionization interval of said gas-filled means consecutively todischarge said pair of energy-storage devices to produce a pair of.output pulses having a predetermined time separation.

8. A high-frequency pulse generator for generating a pair of time-spacedpulses comprising, a pair of energy-storage devices, means for chargingsaid energy-storage devices, gas-filled electron-discharge means havinga predetermined deionization characteristic for discharging each of saidenergy-storage devices but normally maintained in a nonconductivecondition, means for coupling one of said energy-storage devices to saidgas-filled means, svrltching means for coupling the other of saidenergy-storage devices to said gasfllled means, and means for initiatingan electron discharge in said gas-filled means to complete a dischargepath therethrough for said one energystorage device and for operatingsaid switching means with a predetermined time delay less than thedeionization interval of said gas-filled means ii to complete a,discharge path for said other energy-storage device through saidgas-filled means to discharge said energy-storage'devices and produce apair of output pulses having'a-predetermined time separation.

said first gas-filled means, a second gas-filled electron-dischargemeans for coupling the other of said energy-storage devices tosaid'first gasfilled means but normally maintained in a nonconductivecondition, and means for initiating an electron discharge in said'firstgas-filled means to'complete a discharge path therethrough for said oneenergy-storage device and for initiating an electron discharge in saidsecond gas-filled means with a predetermined time delay less than thedeionization interval of said first gas-filled means to complete adischarge path for said other energy-storage device through said firstgas-filled means to dischargesaid energy-storage devices and produce apair of output pulses having a predetermined time separation.

10. A high-frequency pulse generator for generating a pair oftime-spaced pulses comprising, a pair of energy-storage devices, meansfor charging said energy-storage devices, a first gas-filledelectron-discharge means for discharging each of said energy-storagedevices but normallymaintained in a nonconductive condition, said firstgas-filled means including a control electrode and having apredetermined deionization characteristic, a second gas-filledelectron-discharge means including a control electrode for coupling theother of said energy-storage devices to said'first gas-filled meansbutnormally maintained in a 'nonconductive condition, and means forapplying a control signal to said control electrode of said firstgas-filled'means to initiate an electron discharge therein to complete adischarge path 'therethrough for said one energy-storage device and forapplying said control signal to said control electrode of said secondgas-filled means with a predetermined time delay less than thedeionization interval of said first gas-filled means to initiate anelectron discharge in said second gasfilled means and complete adischarge path for said other energy-storage device through saidgas-filled means to discharge said energy-storage devices and produce apair of output pulses having apredetermined time separation.

11. A high-frequency pulse generator for generating a pair oftime-spaced pulses comprising, a pair of energy-storage devicesindividually having a predetermined capacitance, means for charging saidenergy-storage devices, gas-filled electron-discharge means having apredetermined deionization characteristic for discharging each of saidenergy-storage devices but normally maintained in a nonconductivecondition, means for coupling one of said energy-storage devices to saidgas-filledmeans, switching means for coupling the other of saidenergy-storage devices to said gas-filled means, and means forinitiating an electron discharge in said gas-filled means to complete adischarge path therethrough for said one energy-storage device and foroperating said switching means witha predetermined time delay less thanthe deionization intervalof saidgasfilled means to complete adischarge-path forsaid other energy-storage device through: saidgasfilled means to discharge said energy-storage devices and produce-apair of output pulses having a predetermined time'separation, saidcapacitances of said energy-storage devices being so proportioned withreference to the impedances of their respective discharge paths thatsaidpair of output pulses have substantially equal amplitudes.

12. A high-frequency pulse generator for gencrating a pair oftime-spaoed pulses comprising, a pair of transmission lines individuallyhaving in-- ductance and capacitance suchthat the product of' inductanceand capacitance of each line is equal to a preselected constant value,means for establishing a predetermined charge condition on each of saidlines, gas-filled electron-discharge means having a predetermineddeionizationchan "acteristic for discharging each of said lines butnormally maintained in a nonconductive condition, means'for coupling oneof said lines to said gas-filled means, switching means for coupling theother of said lines to saidgas-filled "means, and means'for initiatingan electron discharge in said gas-filled means to complete a dischargepath therethrough for said one line and for op-- crating said switchingmeans with a predetermined time delay less than the deionizationinterval of-said gas-filled means to complete a discharge path for saidother line through said gasfilledmeans to discharge said lines andproduce a pair of output pulses having a predetermined time separation,said capacitances of said lines being so proportioned with reference tothe impedances of theirrespective discharge paths that saidpair ofoutput pulses have substantially equal amplitudes "and pulse durations.

13. A high-frequency pulse generator for generating a pair'oftime-spaced pulses comprising, a 'pair of transmission lines, means forcharging saidpairof linesygas-filled electron-discharge meanshaving'apredetermined deionization characteristic' for discharging each of saidlines but normally maintained in a nonconductive condi tion, 'meansforcoupling one of said lines to said gas-filled means, means including aselectively operable switch for coupling the otherof said lines to saidgas-filled. means through said one line, and means for initiating anelectron discharge in said gas-filled means to complete a dischargepath'therethrough for said one line and for operating said'switch with apredetermined time delay less than the deionization interval of saidgas-filledmeans to complete a discharge path for said other line throughsaid .one line and said gas-filled means to discharge said pair of linesand produce a pair of output pulses having a predetermined timeseparation.

14. A high-frequency pulsegenerator for generating a pairof time-spacedpulses comprising, a pair of transmission lines, means including a firstunidirectional conductive device for simultaneously charging said linesin parallel, gasfilled electron-discharge means having a predetermineddeionization characteristic for discharging each of said-lines butnormally maintained in anonconductive condition, means for coupling oneof said lines to said gas-filled means, switching means including asecond selectively operable andunidirectional conductive device forcoupling said other line to said gas-filled means an electron dischargein said gas-filled means to 13 complete a discharge path therethroughfor said one line and for operating said switching means with apredetermined time delay less than the deionization interval of saidgas-filled means to complete a discharge path for said other linethrough said one line and said gas-filled means to discharge said linesand produce a pair of output pulses having a predetermined timeseparation.

JOHN A. RADO.

REFERENCES CITED The following references are of record in the file ofthis patent:

5 UNITED STATES PATENTS Number Name Date 2,235,385 Rava Mar. 18, 19412,284,850 Smith June 2, 1942

